1. Field of the Invention
This invention generally relates to the retaining plates of a dampening disk assembly, which is used in a clutch of a motorized vehicle. More specifically, the present invention relates to the holes formed in plates, which are located adjacent, the rectangular windows such that these holes reduce wear and increase life span of the plate.
2. Background Information
In general, a clutch disk assembly or dampening disk assembly is used in a clutch of a vehicle. The dampening disk assembly includes an input portion connected with a flywheel on an engine side, and a spline hub connected with a shaft extending from a transmission. The input portion and the spline hub are coupled in a circular direction by a dampening mechanism. The dampening mechanism includes a plurality of coil springs. The input portion includes a friction facing pressed by a flywheel and a pair of disk like plates. The spline hub includes a boss part in which the shaft from the transmission is inlayed, and a flange extending to an outer circumferential side of the boss part. Window holes are formed in the flange, and within each window hole is an elastic portion such as a coil spring. The two plates have rectangular windows (spring supporting part), which are formed by punching and cut and lift in an axial direction, at locations corresponding to the coil springs. These rectangular windows have convex shapes, which are formed by a drawing method. Both circular end parts of the rectangular windows touch both end parts of the coil springs, and operate as a connecting part for transmitting torque therebetween. In addition, the rectangular windows operate as spring casings to seat the coil springs and regulate the coil springs movements in both axial and radial directions.
The rectangular windows (tunnel-type) are formed in the plate main body by drawing, so as to be a convex shape continuing in a radial direction and having a large area which the coil spring touches. As a result, while the spring is compressed and rubs the rectangular window, the window experiences less abrasion.
As the coil spring seated in the rectangular window gets larger, both the axially projecting amount of the rectangular window from the plate main body and the cut and lift angle of the rectangular window get larger.
In the conventional clutch disk assembly mentioned above, the rectangular windows of the retaining plates have round theft holes at the radially inside part on both sides of the rectangular window in a circular direction. Since the theft hole reduces stress, a crack in the retaining plate occurs less often.
However, these prior art plates with these round theft holes do not extend far enough to enable lifting of the rectangular window. Therefore, during the forming of the rectangular window, a crack is easily caused.
An object of the present invention is to make it more difficult to break the rectangular window in the plate used for the dampening disk assembly.
A plate is used for a dampening disk assembly, and supports a coil spring. The plate includes a disk like plate main body and a spring supporting part that is formed at the plate main body. The spring supporting part projects in an axial direction from the plate main body so as to be able to seat the coil spring. The spring supporting part includes an axially supporting part which continues in a radial direction and supports an axially outside part of the coil spring. It also includes a circular supporting part which is formed on both circular side parts of the axially supporting part and supports both ends of the coil spring. A hole which is long in one direction is formed around both corners of its inner circumferential side of the axially supporting part.
The lifted parts of the spring supporting parts have a large angle. Nonetheless, owing to the radially long hole, its amount to extend during forming the window is sufficiently secure, thereby reducing the possibility of cracking.
This long hole is formed to stretch over the axially supporting part, and the plate main body. The hole extends along the same direction as the circular supporting part extends, and has an oval shape. These features result in less cracks being caused during formation of the rectangular window.
The plate includes a disk-like plate main body and a spring supporting part, which is formed at the plate main body. The spring supporting part includes an axially supporting part which projects from the plate main body in an axial direction so as to be able to seat the coil spring, and continues in a radial direction and supports an axially outside part of the coil spring. The spring supporting part also includes a circular supporting part, which is formed on both circular side parts of the axially supporting part and supports both ends of the coil spring. A hole which extends from the radially inside part to the radially outside part is formed on both circular side parts of the axially supporting part.
A dampening disk assembly includes two plates, a hub and a coil spring, where the two plates are fixed to each other. The hub is disposed on a central side of the two plates. Both circular end parts of the coil spring are supported by the spring supporting parts and the coil spring couples the two plates and the hub elastically in a rotary direction.
These and other objects, features, aspects and advantages of the present invention will become apparent to those skilled in the art from the following detailed description, which, taken in conjunction with the drawings, discloses preferred embodiments of the present invention.